any group at the prospect of FOSS being banned. From their perspective, FOSS provides high code visibility and the ability to fix security flaws quickly and quietly. As a result of the findings, any serious consideration of banning FOSS was dropped. The effort to develop a policy on using FOSS instead moved towards a much more even-handed policy that was initiated with the Stenbit open source software policy, that requires U.S. DoD groups to treat FOSS in the same fashion as proprietary software, and subsequently made even more explicit in the 2009 Wennergren clarification of the Stenbit policy. The broader impact can be realized by recognizing that if the security-conscious U.S. DoD had banned FOSS, it is likely many other federal components, state and local governments, corporations, and international groups would have followed suit. The result would have been a world much less friendly both to FOSS and to FOSS-like efforts. Findings Below is the executive summary of the report. The full report was published in multiple formats, which can be found along with related open source software resources on Bollinger's personal website. This report documents the results of a short email-mediated study by The MITRE Corporation on the use of free and open-source software (FOSS) in the U.S. Department of Defense (DoD). FOSS is distinctive because it gives users the right to run, copy, distribute, study, change, and improve it as they see fit, without having to ask permission from or make fiscal payments to any external group or person. The autonomy properties of FOSS make it useful for DoD applications such as rapid responses to cyberattacks, for which slow, low-security external update processes are neither practical nor advisable, and for applications where rapid, open, and community-wide sharing of software components is desirable. On the other hand, the same autonomy properties complicate the interactions of FOSS with non-FOSS software, leading to concerns—some valid and some not—about how and where FOSS should be used in complex DoD systems. The word free in FOSS refers not to fiscal cost, but to the autonomy rights that FOSS grants its users. (A better word for zero-cost software, which lacks such rights, is "freeware.") The phrase open source emphasizes the right of users to study, change, and improve the source code—that is, the detailed design—of FOSS applications. Software that qualifies as free almost always also qualifies as open source, and vice versa, since both